US2077486A - Motion picture film printer - Google Patents

Description

April 20, 1937. c. L. LooTl-:Ns 2,077,486

MOTION PICTURE FILM PRINTER Original Filed Nov. 4, 1932 3 Sheets-Sheet l AMK/fm ATTORN EY ,April 20, 1937. c. I .LooTENs MOTION PICTURE FILM PRINTER Original Filed Nov. 4, 1932 3 Sheets-Sheet 2 PIC TUR E NEG.

.SOL/ND NEG.

P/E'UR MATTE INVENTOR f CHARMS@ A. naf/vs BY W( "/ALWAM.

ATTORNEY April 20, 1937. c. L. LooTENs 2,077,486

MOTION PICTURE FILM PRINTER Original Filed Nov. 4, 1932 3 Sheets-Sheet 3 Ratent'ed Apr. 20, 1937 v UNITED STATES PATENT oFFlce MoTroN PICTURE FILM PRINTER` Original application November 4, 1932, Serial No. 641,247. Divided and this application October 26, 1934, Serial No. 750,167

5 Claims.

My invention relates to a motion picture film printer, this application being a division of my application for. a Continuous film processing method and apparatus filed November 4, 1932,

5 Serial No. 641,247.

' My printer nds great utility as an element in a continuous film processing system wherein, as described in my aforesaid co-pending application, unexposed positive film is introduced at the l ingoing end of a system and is printed, developed,

dried and projected for inspection, by a continuous operation without intermediate rewinding or handling of the film. When my printer is used in such a system, it must be capable of operating l at different speeds, so that if the printer has been stopped for inspection of film, or to put on a different negative, or for any other reason, it will function upon re-starting to deliver lm at a rate faster than nlm is travelling through the 2O developing machine in order to accumulate sufllcient nlm in an elevator to provide for the next stoppage of the printer. The different printing light values, which have been predetermined and which are employed in printing different scenes 25 or successive fractions of ,the film strip, are relative, and presuppose a uniform period of exposure before the printing gate or aperture. Since my printer is capable of being operated at diierent speeds, when the printer runs slow, the exposure 30 is longer and when the printer runs fast, the exposure is shorter, so that unless control is provided for the basic light source the changing light scale will be ineffective.

It is, therefore, an object of my invention to 35 provide a printer capable of operating at different speeds with consequently varying exposure periods, and automatic means for controlling the basic light source so that when the exposure period is increased the amountv of light which reaches the printing aperture is decreased, and when the exposure period.I is decreased the amount of light is increased, the net result being a uniform exposure condition irrespective of the time of exposure. c

To fully utilize the benefits of this present invention, I prefer to employ in conjunction with it an automatic rewind for the picture negative and sound negative as well as light mattes hereinafter described, so that the printer will be wholly automatic and continuous in operation; that is, so it will print any desired number of copies from a specic negative without -the necessity of stopping the printer.

- In the present types of printer used for ex- 55 posing the positive nlm, it is customary to manually control the printingA lights in order to obtain a print of approximately even density. These light changes are usually obtained by varying the diameter of an iris or the voltage of the lamp current. Such changes are not instantaneous and are susceptible to error due to the operator failing to make the necessary manual adjustment of the operating parts.

It is, therefore, another object of my invention to provide a printer in which the light changes are effected by means wholly automatic and not requiring the intervention of an operator after the negative lm and the light control elements are once properly threaded in the machine.

In the drawings,

Figure l is a front elevation of the printer.

Figure 2 is an elevation, looking in the same direction as Figure 1, showing fragments of the printer and showing the continuous negative and light matte magazine to illustrate the relation of the printer and the magazine.

Figure 3 is a fragmentary cross-section taken on the line 3--3 of Figure 1.

Figure l is an enlarged detail of one of the light control gates shown in Figure 1.

Figure 5 is a fragmentary front View of a shutter element taken on the line 5--5 of Figure 4. A

Figure 6 is a similar fragmentary view of the shutter element with the parts in different operative positions.

Figure 7 is a sectional View of another light aperture shield in the printer taken on the line 'l-I of Figure 4.

Figure 8 is a cross section of the same device taken on the line 8 8 of Figure 7.

Two printing elements 40 and 4| for picture and sound, respectively, are located in proximity on a suitable frame. Film passes continuously through the printing elements by means of driven film sprockets 42 43 and 44. These sprockets are rotated through shafts and gears, not shown, which derive their movement from a main power source such as an electric motor operating through a shaft 4l, gears 48 and 49 and a vertical shaft 50. From the shaft 5D, power is transmitted to sprockets 42, 43 and 44 by direct gear and shaft drive.

Picture negativa after travelling through a vacuum cleaner 5|, cornes in contact with the raw stock F at sprocket 42 and travels with the raw stock past the printing gate 52 of the printing element 40, coming out over rollers 53 and 54, then passing through another vacuum cleaner aar/,ne

hetoreheirlgwulrmilvlpinthecontinuousuega-` theseparationofwhichinmoreorlessdegree tive magasine. Bound-negative fed ingelementlhthenceovertbesprocketuand outtothemagasine. 'lhepositiveiimtravellinginthedirectionofthearrowontheleft when the printer l the printing gate a longer time, and therefore, requires less light: on the other hand, when the Mpnnrspeeds unime expurembrlefer, ma

theshaft Il isrotating,theyweights outwardly under centrifugal force, thereele'vating a collar 'Il which freely encloses Il. Whenthepartswereinthepositions shutterwascompletelyclosedasinldgure; 45 but, when the printer is started. and collar 1I travels upwardly, it swings bar 1I, which is pivotedat 1lonaframemember1'Landinswinging upwardly elevates a link 1l. 0n the end of bar 1I is attached a weight 15a. The function Wofthisweightistoloadtheiiy weights sothat weight control system may be changed. Piv- 55 oted at Il is a crank .l which is pivotally mounted at Il; and a slotted end of the crank moves in the direction of the arrow l2. 'I'his movement is transmitted through a pin I3 to a horizontal bar u adapted to reciprocate between two pairs 60 of rollers and It. y

n this horizontal bar Il are cams 81, the faces of which engage rollers Il, and in traveling in the direction of the arrow l2 raise the rollers.

Each roller Il is pivoted to a vertical member l of a linkage Il, which is drawn upwardly by the movement of the horizontal bar Il in the direction of the arrow I2. 'Ihls upward move- 70 ment of the linkage 8| causes the rotation in opposite directions of two accurate shields 92 and Il. Shield l! rotates in the direction of the arrow 92a, and shield 9J rotates in the direction of the arrow 93a. The two shields have comple- 75 mentary V-shaped cut-away portions 94 and Si,

provides anaperture oi' greater or less area.

Shieldlisrotatedupwardlybymeans ofa cranklpivotingatlkandtheshieldisr tateddownwardly'byacrankl'lhavingthesame pivotalpoint Il. Thusitwillbeseenthat as Figures 5 and 6, the crank III, which is secured to the and transmits the rotative force of the Crank $1 is secured to asleeve IUI, which is secured to shield l2 and transmits to the shield l! the rotative force of crank 9|. 'Ihe sleeve ill, which nds a bearing in a Journal III. in turn provid a bearing lor the pin III.

Due to lack of uniformity inthe exposure of negatives, it is found in practice that different scenes in a single reel of negative will be of diiferent densities; and as the release print should have an even density throughout. it is necessary to vary the volume or intensity of the light in the printer so that the release print, ii' developed under constant conditions. will have a uniform` density and quality. Ihe light change is eifected in the old methods of film printing by having an operator manually re-adJust the printing light for printing each scene, sometimes as high as two hundred changes in a single reel.

In my printer, I provide an'automatic light change, which, having once been set, will function without the intervention oi' an operator to change the light according toa predetermined schedule.

The light change element is in the form of a iiim matte having transparent center strips of diiferent widths, depending upon the amount oi' light which it is desired to pass through. The matte is made by previously exposing a 111m behind diiferent shields'of the proper widths, then developing the iilm `until the sides are opaque, while the unexposed center remains transparent. 'Ihe method of preparing this light matte is the subject of another application for patent. Ihere is one light matte for the pictme negative and another light matte for the sound negative. Each matte is preferably in the form of a closed loop which, as shown in Figure 2, can be run through the printing device an indenite number of times. In the interest of economy, I make the two light mattes relatively shorter than the picture negatives and sound negatives respectively. approximately in the ratio of one to four.

Referring to'Figure 2, the course of the picture light matte through the printing element 40 may be readily traced. It is observed in greater detail in Figure 4, where it will be seen that the matte travels between the control shutter 64 and the illm`to be printed, passing adjacent to an aperture H0 shown in Figures 7 and 8. The horizontal dimension or length of the aperture is fixed and is the width of the iilm light matte. The vertical dimension or dimension parallel to the travel of the light matte is adjustable by means of the screw and cam mechanism ill shown in Figure '1. The purpose of this adjustment is to provide a means of balancing the light of the picture printing aperture with thelight oi the sound track printing aperture. 'I'here is a similar adjustable aperture on the sound track printing head element. 'Ihis adjustment may also be used to raise the general level of printing light for both picture and sound printing elements. l

In this connection'I ilnd it good practice to use a rheostat' in'series with the picture and sound printing lamps so that the voltage impressed on the lamp can be changed. I have found that this is an ideal means for controlling the overall light intensity, and I control the light intensity so that the developing time required l0 isthat to produce optimum results insofar as contrast is concerned. Also when the voltage on the printing lamps is decreased, the color temperature of the filament is decreased so that printing is accomplished with a more yellow light. In actual practice this seems to increase the contrast of Aprinting thereby in part compensating for the .contrast lost in a continuous printer. After the proper width adjustments have been made to aperture H0, the printing light intensity is controlled by the various widths of light matte changes travelling through the gate 65. The light matte widths are selected in advance, and are .joined together in lengths proportionate to the negative scenes. A marker on the sprocket which puns the light matte through the gate 65 serves as a synchronizing medium which is matched with a mark on the light matte. In this way the light change is made at the same time the scene changes.

A similar device is employed in conjunction with the sound printing element li.

As before noted, the picture negative is vacu-' um cleaned before and after the printing operation. The other .films may be cleaned if it is found essential to do so.

In Figure 2, the continuous negative and light matte magazines are shown. Each one consists of a plurality of lm supporting rollers arranged concentrically, the two light matte magazines 40 being inside, due to their smaller capacityfand the picture and sound negative magazines, storing greater footage, being located outside. The two negatives and the two light mattes are each in the form of endless loops, so that they may be run through the printer repeatedly without stopping the apparatus to re-thread the film. The films are carried over the rollers of the respective magazines in a plurality of layers sufilcient in number to store the illms and properly confine them.

Arrows indicate the direction of travel of the four films, each being fed to the printing elements from inside the illm layers by means of sprockets |20, I 20a, I20b, and Illlc. After passing through the printing elements, the lms are taken up on the outside layers.

The printer may be used without the continuous magazines. In that case suitable spindles are mounted on the frame structure for carrying ordinary illm reels. The printer is threaded in the same way as heretofore described, the negatives and light mattes. after passing through the printing elements. being taken up on ordinary rewinders. At the end of each negative reel, it is necessary to stop the printer and re-thread it; but the negatives may be alternately run through backwards in order to eliminate an intermediate rewinding operation.

What I claim is:

1. A nlm printer comprising a printing light, a printing gate, means to pass a negative and a positive in printing relation past the printing gate, a light aperture the area of which is automatically enlarged or diminished according to the speed of said means interposed between the printing light and the printing gate, and means for changing the relationship between speed and area of light aperture.

2. Inamotionpictureillxnprinterinwhichnegative and positive lm strips are caused to travel continuously before a printing light, the period of exposure of any given section of lm being determined by the linear speed at which the lms travel before the light, a. diaphragm to regulate the amount of light which reaches the film, a control being coupled with the operating mechanism of the printer and responsive to the operating speed thereof and coupled also with the diaphragm to increase or decrease the amount of light reaching the films, said control including a device which can be adjusted to cause the control to respond to a given operating speed in a different degree.

3. A lm printer comprising a printing light, a printing gate, means to pass a negative and a positive in printing relation past the printing gate, members forming a light aperture of variable area between the hght and the gate, a regulating device cooperating between the said means and the said members to increase or decrease the area of the aperture inversely to change in speed of the said means, said regulating device including an adjusting element adapted to change the relationship between speed and area of light aperture.

4. A film printer comprising a printing light, a printing gate, means to pass a negative and a positive in printing relation past the printing gate, members forming a light aperture of variable area between the light and the gate, a regulating device cooperating between the said means and the said members to increase or decrease the area of the aperture inversely to change in speed of the said means, said regulating device including fly weights and a counterbalance opposing the fly weights, the counterbalance being adjustable to vary the eiectiveness of the fiy weights so that the relation between speed and area of light aperture may be changed.

5. A film printer comprising a printing light, a printing gate, means to pass a negative and a positive in printing relation past the printing gate, members forming a light aperture of variable area between the light and the gate, a regulating device cooperating between the said means and the said members to increase or decrease the area of the aperture' inversely tochange in speed oi the said means, said regulating device including ily weights, a connecting link caused to shift by the ily weights and a counterweight upon the connecting link movable along said link to vary the eiectiveness of the ily weights at any given speed.

CHARLES L. LOOTENS.

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